1. Field of the Invention
The present invention relates to an electronic apparatus including a main body of the apparatus and a case for housing the main body and further including, inside of the apparatus, a cooling unit that circulates a liquid cooling medium to cool components constituting the main body, and a cooling medium replacement cartridge used for the electronic apparatus.
2. Description of Related Art
Projectors have been used for presentation in meetings, academic conferences, exhibitions, or the like, or to watch movies at home. A projector of this type includes a light source, a optical modulator that modulates a light beam emitted from the light source in accordance with image information to form an optical image, and an optical device disposed on the upstream and downstream of the optical modulator and having a plurality of optical components that perform optical conversion of an incident light beam. The projector forms an optical image and projects the image in an enlarged manner by the optical device.
With the increase in the luminance of the projector and reduction in the size thereof, the temperature of the optical modulator and optical components disposed in the projector has been being increased remarkably in recent years. In addition, the optical modulator and optical components are easily affected by heat and therefore subject to heat deterioration. The heat deterioration of the optical modulator and optical components may adversely affect formation of an optical image to pose a problem for the maintenance of functions of the projector. To cope with this problem, an air-cooling type cooling system that sends a cooling air using a fan or the like has been generally used in the conventional projector. However, the air-cooling type has a limitation in its heat radiation capability and needs to rotate the fan at high-speed or needs to use a large-sized fan for the purpose of assuring required air volume, impeding reduction of noise and size of the projector. Therefore, a new cooling system that effectively cools the optical modulator and optical components has been considered.
A projector in which an optical component (polarization plate) includes a liquid cooling section is known as a cooling system that solves the above problem (for example, see Reference: Japanese Patent Laid-Open Publication No. Hei 4-54778). The projector disclosed in the Reference includes a liquid cooling section constituted by a frame body with two transparent panels disposed in the passage of a light beam. A cooling medium (cooling liquid) such as ethylene glycol is filled up in the frame body. In a state of being attached to a polarization plate, the liquid cooling section cools the heat of the polarization plate. Since liquid has a higher specific heat and higher transfer capability than air, the projector using the liquid cooling section not only effectively cools the polarization plate but also contributes reduction of noise because fan rotation noise and wind noise are not generated.
In the projector disclosed in the Reference, an optical image is formed based on the light beam that has been transmitted through the cooling medium disposed on an illumination optical axis. Accordingly, if discoloration of the cooling medium is caused due to aging degradation, heat degradation, or the like, or if impurities are introduced into the cooling medium, the discoloration and introduced impurities adversely affect a projection image. In this case, therefore, it is necessary to replace the cooling medium with a new one. However, complicated works such as disassembly of the projector are required to replace the cooling medium.